Longitudinal Assessment of ADAMTS13 Activity Helps Predict Recurrence of Immune Thrombotic Thrombocytopenic Purpura: Results From the German TTP Registry

On Sunday, Charis von Auer-Wegener of the University Medical Center of the Johannes Gutenberg in Mainz, Germany, presented results from research investigating the role of ADAMTS13 activity in predicting recurrence of immune thrombotic thrombocytopenic purpura, or iTTP. Severe deficiency of ADAMTS13 activity resulting from autoantibodies is the primary cause of iTTP, of which about 30% may experience disease exacerbation and/or relapse. The challenge, however, is that there is not a reliable biomarker that predicts disease recurrence.

Auer-Wegener commented that patients were enrolled who had an acute bout or remission. Prospective follow-up with ADAMTS13 activity measurement was planned at three-month intervals, with the predictive value being assessed using Cox regression. A total of 103 iTTP patients were enrolled and followed for 140–1,271 days; 85 had at least two visits, with 13 patients relapsing. During the observation period, 44 out of 85 patients had continuously normal ADAMTS13 activity (≥50%), and none of them relapsed. Two patients had ADAMTS13 activity continuously between 25% and 50%, with none relapsing. One patient had ADAMTS13 activity continuously between 10% and 25% and did not relapse. Nine patients had ADAMTS13 activity continuously <10%, with eight relapsing to date. Thirty patients had undulating parameters of ADAMTS13 activity and did not relapse. Ten out of 85 patients showed a steep decline of ADAMTS13 activity; five relapsed.

Auer-Wegener concluded that the work showed that longitudinal quarterly assessment of ADAMTS13 activity is of critical value for predicting iTTP recurrence, suggesting the need for additional off-label therapeutic coverage (with perhaps rituximab, corticosteroids, or caplacizumab) to prevent recurrence in the long-term management of patients with iTTP.

Read the full abstract here.